From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Thu, 23 Apr 2009 07:12:59 +0000 (+0930)
Subject: virtio-rng: Remove false BUG for spurious callbacks
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e5b89542ea18020961882228c26db3ba87f6e608;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

virtio-rng: Remove false BUG for spurious callbacks

The virtio-rng drivers checks for spurious callbacks. Since
callbacks can be implemented via shared interrupts (e.g. PCI) this
could lead to guest kernel oopses with lots of virtio devices.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index d0e563e4fc39..86e83f883139 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -37,9 +37,9 @@ static void random_recv_done(struct virtqueue *vq)
 {
 	int len;
 
-	/* We never get spurious callbacks. */
+	/* We can get spurious callbacks, e.g. shared IRQs + virtio_pci. */
 	if (!vq->vq_ops->get_buf(vq, &len))
-		BUG();
+		return;
 
 	data_left = len / sizeof(random_data[0]);
 	complete(&have_data);